Insulator for electric systems



June 21, 1932. H. KLEMM- 1,863,531

INSULATOR Fon ELECTRIC SYSTEMS Filed July 9. 1929 2 Sheets-,Sheet l AlV/l/I/ I Ill/I H.' KLEMM INSULATOH FOR ELECTRIC SYSTEMS Filed July 9, 1929 2 Sheets-Sheet 2 Patented June 21, 1932 UNiTEDfsTATEs PATENT oFFIcE/ 'Y HANS KLEMM, OF DRESDEN', GERMANY, ASSIGNOR TO THE FIRM.: KOCH & STERZEL f AKTIENGESELLSCHAFT, OF DRESDEN, SAXONY, GERMANY INSULATOR FOR ELECTRIC` SYS'IEIIISv Application led July 9, 1929, Serial No.

My invention relates to insulators for electric systems andit is an object of my in vention to reduce the length of such insulators. To this end I so arrange the terminal 'connection or connections of the appliance or appliances which are arranged in the insulator, that they are concealed by the insulator.

In insulators as heretofore designed the terminal connection or connections projectedy from the end, or ends, of the insulator and therefore in order to prevent surface-leakage from such terminal connections to grounded parts on the insulator, it was necessary to u make the insulator rather long in order to obtain a long surface-leakage path from the terminal connections to the grounded part. This drawback is eliminated according to my invention in which the terminal connections are concealed in the insulator, that'is, with the end, or ends, of the insulator projecting beyond the terminal connections, so that the surface-leakage path from the connections to the grounded part is long and broken, notwithstandingr the fact that the terminal `connections are nearer to the grounded part than in the usual insulators.

My invention may be adapted to any type of insulators. It is particularly suitable for the insulators of measuring transformers but it may also be adapted to leading-in insulators which only contain a primary.

It will be understood that by arranging the terminal connections within the insulau' tor, the necessity of providing a. considerable distance between such connections and any grounded part of the insulator, and therefore making the insulator very long, is eliminated. The length of the surface-leakage path may be further increased by providing grooves on the projecting end or ends of the insulator. f

My novelarrangement is particularly favorable when the transformer is connected with parts under current by plug and socket-connectionsv as in this case the projecting ends may be extended so as to shield the connection, and separate insulating sleeves are not required.

In the drawings affixed to this specifica- 376,950, and n'Germany July 14, 1928.

tion and forming part thereof, a transformer with a pot-shaped insulator, a leading-in in sulator, and two examples of connections with electric systems are illustrated diagrammatically by way of example.

In the drawings Fig. 1 is a somewhat diagrammatic axial section of a pot-shaped insulator and transformer unit,

Fig. 2 is a central section of a similar unit, drawn to alarger scale and showing more details,

Fig. 3 is a section taken at right anglesto the section in Fig. 2, and viewed from the right in that figure,

Fig. 4 is a central section of a leading-in unit,

Fig. 5 is a partly sectional elevation of 'a leading-in transformer as shown in Fig. 4, and of a` single-conductor leading-in insulator, in combination with an oil switch,

Fig. 6 illustrates the adaptation of the leading-in. transformer as shown in Fig. 4 to a plug-and-socket connection for bus bars.

Referring now to the drawings, and first` to Fig. 1, 11 is the insulator of a pot-shaped current-measuring transformer, 28 is a groundc ed casing surrounding the lower end of the insulator 11, 12 is a tunnel in the insulator which is dened therein by a transverse tube 13 of substantially square section, 14 is the primary coil of the transformer which is placed on the outside of the tube 13, and 16 is the middle leg of a. shell iron core the yokes ofy whichextend along the sides of the insulator. As shown, the middle leg 16 is in` serted in the tunnel 12 and is surrounded by the secondary coil 15. 25 is a ridge projecting from the inside of the insulator 11 above the tube 13, and 23 and 24 are parallel bridges or supports of insulating material which are placed on the upper and lower faces of the ridge 25 and held thereon by screws which are not shown in this figure but ,will be described below. The ends 17 and 18 of the primary coil 14 are taken to binding posts 19 and 20 on the upper bridge 23, and the ends of the secondary coil 15 are taken to binding posts at the side of the casing 28, which are not shown in this figure.

As will appear, the upper edge 29 of the insulator 11 projects beyond the primary binding posts 19, 20, and in this manner the length of the unit is reduced as compared with the usual type in which the binding posts project freely from the upper end of the insulator.

Referring now to Figs. 2 and 3, corresponding parts have been marked with the same reference numerals as in Fig. 1. Fig. 3 shows the binding posts 21 and 22 at the side of the casing 28 to which the ends of the secondary coil 15 are taken, as mentioned above, and both figures show in detail the bridges 23 and 24, 26 being screws inserted in the bridges so that the bridges will beheld with the ridge 25 between them, without being cemented thereto. If desired, astrip of resilient material may be inserted between the ridge 25 and one of the bridges, or both bridges. In the present instance it has been assumed that the bridges are not of insulating material and therefore they have been divided at the centre intermediate the binding posts 19 and 20 for the ends 17 and 18 of the primary coil 14, and an insulating layer 27 has been inserted between the two parts of the upper bridge 23.

In the present instance, a plug-and-socket connection has been shown in combination with the binding posts 19 and 20. Sockets 30 and 31 are secured on the bridge 23 in connection with the posts 19 and 20, and partly project from the upper end 29 of the insulator 11. 32 and 33 are plugs adapted to cooperate with the sockets and inserted in the bottom of a cup 34 of insulating material which projects downwardly beyond the edge 29 of the insulator 11 and overlaps the insulator at some clearance. 35 is a grounded metallic shield for the cup 34 which is provided with a flange 37 at its lower end, 36 is a corresponding flange at the upper end of the casing 28, and 38 are screws for connecting the flanges. This connection is provided with the object of relieving the plugs 32 and 33 of the weight of the transformer. 39 are handles for facilitating the extraction of the. casing 28. The upper edge of the casing extends beyond the flanges and is held in a groove on the insulator by means of a ring 1 of rubber or the like.

In this manner, a serpentine path is provided between the connections 30, 32, 31, 33 on the one hand and the grounded metal casing 35 on the other, and by suitably selecting the lengths of the overlapping ends of the insulator 11 and the cup 34, it is possible to maintain this long sparking-over path during the separation of the plugs and sockets so that the effective insulat-ion described is maintained also while the connection is being separated.

Referring now to Fig. 4 this shows a leading-in insulator the ends 40 .and 41 of which project beyond the terminals 19 and 20, respectively, which in the present instance are secured on bridges 23 and 23 at opposite ends of the insulator, the bridges being supported on ridges 25 and 25 of the insulator 11 by means of screws and auxiliary bridgesl as described with reference to Figs. 1 to 3. 49 is a flange on the insulator by which it may be secured to a part of an electric system. v

Referring now to Fig. 5, 42 is an oil switch in a frame 50 which is adapted to move on wheels along a track 48. 51 is a leading-in `transformer of the type described with reference to Fig. 4 but with a plug-and-socket connection at its outer end. The insulator is secured to the frame 50 with its flange 49 and the inner terminal 20 of its primary coil 14 is connected with one of the terminals of the,

oil switch 42. 45 is a plug in the wall of a casing 2, to which plug the end of a cable 44 is connected. 46 is the corresponding socket on the insulator 51, and 34 is a cup surrounds ing the connection as and for the purpose described with reference to Figs. 2 and 3, but here arranged within the inside diameter of the insulator. 57 is a leading-in insulator which is secured in the frame 50 by means of a sleeve or the like. The primary of this insulator is connected with the other terminal of the oilswitch 42 at the inner end, and with a socket 58 at the outer end. 45 is a plug in the casing 2, 34 is the cup which shields the connection in the manner described, and 43, 43 are bus bars in the casing 2 to which the plug 45 is connected.

Referring now to Fig. 6, this illustrates twoy systems at three bus bars 52, 53 in a casing 3, which are connected with plugs 32 and 33, respectively. The plugs cooperate with sockets 30 and 31 at the ends of the insulator 11, which in this case has the shape of the letter U, but otherwise resembles the insulator in Fig. 4. The ends 17 and 18 of the primary coil 14 are connected with the sockets 30 and 31, respectively, as described with reference to Figs. 2 and 3. 34 are cups surrounding the two connections as described. The ends of the secondary coil 15 are taken to plugs 56.

It will be understood that in the const-ructions illust-rated flexible connect-ions are dispensed with altogether and that separate insulat-ing sleeves for the connections are not required.

I wish it to be understood that I do not .desire to be limited to the exact details of construction shown and described for obvious modifications will occur toa person skilled in the art.

1n the claims affixed to this specification no selection of any particular modification of the invention is intended to the exclusion of other modifications thereof and the right to subsequently make claim to any modification not covered by these claims is expressly reserved.

I claim:

l. A transformer comprising a pot-shaped insulating casing, a primary coil arranged y within said casing, two terminal connections for said primary coil also within said casing and spaced apart from the adjacent end of said casing, a ridge on the inside of said casing for supporting said terminal connections, a support for said terminal connections adapted to engage one face of said ridge, a bridge adapted to engage its opposite face and an adjustable stay extending from said support to said bridge.

2. A transformer comprising a primary, a terminal connection for said primary, an insulating casing enclosing said primary, means within said casing for supporting said terminal, having a neck portion forming part of and being integral with said casing, said neck portion extending considerably beyond said terminal and forming part oi' the leal age path between said terminal and ground.

3. A pot-shaped current transformer comprising an insulator having a closed bottom and a neck portion both integral with its body, a primary within said insulator and a terminal connection for said primary arranged in said neck portion, said neck portion extending considerably beyond said terminal and forming part of the leakage path between said terminal and ground.

4. A pot-shaped current transformer com prising an insulator having a body and a closed bottom and a neck portion both formed integral with said body, a tunnel portion eX- tending transversely across said insulator, a primary within said insulator, said primary being wound on thefoutside of said tunnel portion, and a terminal connection for said primary arranged in said neck portion, said neck portion extending considerably beyond said terminal and forming part of the leakage path between said terminal and ground.

5. A pot-shaped current transformer comprising an insulator having a body and a closed bottom and neck portion, both formed integral with said body, a primary within said insulator and two terminal connections for said primary arranged in said neck portion, said neck portion extending considerably beyond said. terminals and forming part of said leakage paths between said terminals and ground. A

6. A transformer comprising a primary, two terminal connections for said primary, said terminal connections being arranged. on opposite ends of said primary, and a tubular insulating casing enclosing said primary and neck portions forming part of and being integral with said casing, each neck portion ei;- tending considerably beyond one of said terminals and forming part of the leakage path between the associated terminals and ground.

7. A transformer comprising a primary, a terminal connection for said primary, an insulating casing enclosing said primary, a neck portion formed integral with said casing and extending considerably beyond said terminal, and a ridge on the inside of said neck portion for supporting said terminal.

8. A pot-shaped current transformer comprising an insulator having a body and a closed bottom and a neck portion formed in tegral with said body, a tunnel portion eX- tending transversely across said insulator, a primary within said insulator, said primary being wound on the outside of said tunnel portion, a terminal connection for said primary in said neck portion and spaced from the edge thereof, and a ridge on the inside of said neck portion for supporting said terminal.

9. A transformer comprising a primary, a terminal connectionfor said primary, an insulating casing enclosing said primary, a neck portion formed integral with said casing and extending considerably beyond said terminal, an insulating cup adapted to koverlap said neck portion and a terminal connection in said cup for cooperation with said terminal connection for said primary, said cup being of such .length as to overlap said neck portion until said connections have been separated.

In testimony whereof I aiiix my signature.

HANS KLEMM. 

